Skip to main content
VulnerabilityPublished

CVE-2026-48804: python-socketio · Binary attachment accumulation can cause denial of service

Affects python-socketioSource GCVE Database

0
Compare
Authoritative record:CVE-2026-48804· High 7.5

Not known to be exploited · CVSS 7.5 High : upgrade to 5.16.2 soon.

Data as of 29 Oct 2026, 19:04 UTC

CVSS 3.1 base score
7.5High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.4% chance of exploitation in 30 days – higher than 41% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 5.16.2
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 11 Aug 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.

What to do

Upgrade python-socketio to 5.16.2.

Affected software

ProductAffectedFixed in
PyPIpython-socketioAffected
  • <5.16.2
Fixed in
  • 5.16.2

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

### Impact The python-socketio server stores binary `EVENT` and `ACK` messages in memory while it waits to receive their binary attachments. Once all the attachments are received, these messages are then processed. An attacker can submit a binary message and intentionally omit sending one or more of its attachments to cause the message along with the partial list of received attachments to stay in memory for a long time. ### Patches Version 5.16.2 takes the following measures to address this issue: - Binary packets are only accepted from authenticated clients. - When a client disconnects, the server checks if there is a partial binary message being held for the client and deletes it.

References

Community reviews

Loading reviews…